Submission #674646

#	Time	Username	Problem	Language	Result	Execution time	Memory
674646		tamthegod	Teams (CEOI11_tea)	C++17	50 / 100	2574 ms	184076 KiB

tea

// Make the best become better
// No room for laziness
#include<bits/stdc++.h>

#define pb push_back
#define fi first
#define se second
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int maxN = 1e6 + 5;
const int mod = 1e9 + 7;
const ll oo = 1e9;
int n, a[maxN], id[maxN];
int f[maxN], trace[maxN];
int dp[maxN];
pair<int, int> st[4 * maxN];
void ReadInput()
{
    cin >> n;
    for(int i=1; i<=n; i++)
        cin >> a[i];
}
void update(int id, int l, int r, int pos, pair<int, int> val)
{
    if(l == r)
    {
        st[id] = val;
        return;
    }
    int mid = (l + r) / 2;
    if(pos <= mid) update(id * 2, l, mid, pos, val);
    else update(id * 2 + 1, mid + 1, r, pos, val);
    st[id] = max(st[id * 2], st[id * 2 + 1]);
}
pair<int, int> get(int id, int l, int r, int u, int v)
{
    if(l > v || r < u) return {-oo, -oo};
    if(l >= u && r <= v) return st[id];
    int mid = (l + r) / 2;
    return max(get(id * 2, l, mid, u, v), get(id * 2 + 1, mid + 1, r, u, v));
}
bool chk(int val)
{
    memset(st, -3, sizeof st);
    memset(dp, -3, sizeof dp);
    dp[0] = 0;
    for(int i=1; i<=n; i++)
    {
        update(1, 1, n, i, {dp[i - 1], i});
        int t = id[i];
        int l = max(1, i - val + 1), r = i - a[t] + 1;
        pair<int, int> tmp = get(1, 1, n, l, r);
        dp[i] = tmp.fi + 1;
    }
    //cout << dp[4];exit(0);
    return dp[n] == f[n];
}
void Print(int val)
{
    memset(st, -3, sizeof st);
    memset(f, -3, sizeof f);
    f[0] = 0;
    for(int i=1; i<=n; i++)
    {
        update(1, 1, n, i, {f[i - 1], i});
        int t = id[i];
        int l = max(1, i - val + 1), r = i - a[t] + 1;
        pair<int, int> tmp = get(1, 1, n, l, r);
        f[i] = tmp.fi + 1;
        trace[i] = tmp.se;
    }
    cout << f[n] << '\n';
    int i = n;
    while(i)
    {
        cout << i - trace[i] + 1 << " ";
        for(int j=i; j>=trace[i]; j--)
            cout << id[j] << " ";
        i = trace[i] - 1;
        cout << '\n';
    }
}
void Solve()
{
    iota(id + 1, id + n + 1, 1);
    sort(id + 1, id + n + 1, [](int i, int j)
    {
        return a[i] < a[j];
    });
    memset(st, -3, sizeof st);
    memset(f, -3, sizeof f);
    f[0] = 0;
    for(int i=1; i<=n; i++)
    {
        update(1, 1, n, i, {f[i - 1], i});
        int t = id[i];
        int l = 1, r = i - a[t] + 1;
        pair<int, int> tmp = get(1, 1, n, l, r);
        f[i] = tmp.fi + 1;
    }
    int low = a[id[n]], high = a[id[n]] + 100, mid;
    while(low <= high)
    {
        mid = (low + high) / 2;
        if(chk(mid)) high = mid - 1;
        else low = mid + 1;
    }
    //cout << low;return;
    Print(low);
}
int32_t main()
{
    //freopen("x.inp", "r", stdin);
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    ReadInput();
    Solve();
}

Compilation message (stderr)

tea.cpp: In function 'bool chk(int)':
tea.cpp:47:29: warning: 'void* memset(void*, int, size_t)' writing to an object of type 'struct std::pair<int, int>' with no trivial copy-assignment [-Wclass-memaccess]
   47 |     memset(st, -3, sizeof st);
      |                             ^
In file included from /usr/include/c++/10/bits/stl_algobase.h:64,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from tea.cpp:3:
/usr/include/c++/10/bits/stl_pair.h:211:12: note: 'struct std::pair<int, int>' declared here
  211 |     struct pair
      |            ^~~~
tea.cpp: In function 'void Print(int)':
tea.cpp:63:29: warning: 'void* memset(void*, int, size_t)' writing to an object of type 'struct std::pair<int, int>' with no trivial copy-assignment [-Wclass-memaccess]
   63 |     memset(st, -3, sizeof st);
      |                             ^
In file included from /usr/include/c++/10/bits/stl_algobase.h:64,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from tea.cpp:3:
/usr/include/c++/10/bits/stl_pair.h:211:12: note: 'struct std::pair<int, int>' declared here
  211 |     struct pair
      |            ^~~~
tea.cpp: In function 'void Solve()':
tea.cpp:93:29: warning: 'void* memset(void*, int, size_t)' writing to an object of type 'struct std::pair<int, int>' with no trivial copy-assignment [-Wclass-memaccess]
   93 |     memset(st, -3, sizeof st);
      |                             ^
In file included from /usr/include/c++/10/bits/stl_algobase.h:64,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from tea.cpp:3:
/usr/include/c++/10/bits/stl_pair.h:211:12: note: 'struct std::pair<int, int>' declared here
  211 |     struct pair
      |            ^~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10